Apparatus for the reduction of metals or alloys



1962 s. HIRST ETAL 3,049,035

APPARATUS FOR THE REDUCTION OF METALS OR ALLOYS Filed Nov. 12, 1958 4 Sheets-Sheet 1 I? I7 9 23 3O 25 26 INVENTORS: Sfan/ey Hirsf, y

William Gila/Zea Asfon BYQMLM M ATTORNEYS.

Aug. 14, 1962 s. HIRST ETAL 3,049,035

APPARATUS FOR THE REDUCTION OF METALS OR ALLOYS Filed Nov. 12,1958 4Sheets-Sheet2 LL/L z: 23F

9 i I 48 I I H 5 H L I I0 H; s: :1 5 Is i :i i a 12 IN VE N TORS;

Sfan /e y Hirsf, 1

William Charles Asfon,

g- 1952 s. HIRST ET AL 3,049,035

APPARATUS FOR THE REDUCTION OF METALS OR ALLOYS Filed Nov. 12, 1958 4 Sheets-Sheet 3 FIG. 3.

INVENTORS:

Sfan /e y Hirsf; fir Wi/liam Char/es Asfon,

GYM W W ATTORNEYS.

Aug. 14, 1962 s. HIRST ETAL 3,049,035

APPARATUS FOR THE REDUCTION OF METALS OR ALLOYS Filed Nov. 12, 1958 4 Sheets-Sheet 4 INVENTORS STfl/VLEY //ms 7 Maw/v C/IJ/FL'S 45 Tom ZAAW AMW ATTORNEYS 3,M9,d35 Patented Aug. 14, 1962 ffice 3,049,035 APPARATUS FOR THE REDUCTION OF METALS R ALLOYS Stanley Hirst, Sutton Coldfield, and William Charles Aston, Quinton, England, assignors to Imperial Chenncal Industries Limited, London, England, a corporation of Great Britain Filed Nov. 12, 1958, Ser. No. 773,449 Claims priority, application Great Britain Nov. 13, 1957 Claims. (CI. 78-36) This invention is concerned with apparatus for the reduction of metals or alloys and, in particular, is concerned with apparatus for reducing those metals or alloys in sheet or strip form which normally are regarded as being difficult to reduce, by rolling, below a specific thickness due to their high strength. An example of such a metal is titanium or an alloy thereof.

It has been found in practice that titanium sheet can be produced readily by conventional rolling methods, but there is on any one mill, at lower limit to the thickness of sheet which is obtainable. When that thickness has been reached, further reduction becomes most difficult and no matter what additional load is applied no further reduction occurs.

According to this invention there is provided a method for reducing the thickness of metal in strip form by means of a pair of conforming tools, one at least of which continuously reciprocates towards and away from the other so as to compress a strip which, during the whole or some of the period when the tool is, or tools are, moving away from and towards the strip, is fed through the gap formed by the tools by such small increments that a small incremental length of the strip, during its passage between the tools, is gradually reduced, without the introduction of any substantial discontinuity between one incremental length and the next incremental length, to a desired thickness by successive compressions between the conforming tools.

According to the invention there is also provided a method for reducing the thickness of metal in strip form by means of a pair of conforming tools, one at least of which continuously reciprocates towards and away from the other, the amplitude of reciprocation being automatically controlled so that any deviation from a desired amplitude is corrected, so as to compress a strip which, during the whole or some of the period when the tool is, or tools are, moving away from and towards the strip, is fed through the gap formed by the tools by such small increments that a small incremental length of the strip, during its passage between the tools, is gradually reduced, without the introduction of any substantial discontinuity between one incremetnal length and the next incremental length, to a desired thickness by successive compressions between the conforming tools.

According to the invention there is also provided an apparatus for reducing the thickness of metal strip which comprises a pair of conforming tools, means for effecting reciprocation of at least one of the conforming tools towards and away from the other and means for feeding the strip by small increments through the gap formed by the conforming tools during the Whole or part of the period when the tool is, or tools are, moving away from and towards each other, the working surfaces of the conforming tools, at least in the region of the entry side of the strip, converging towards each other.

Preferably reciprocation of the conforming tool is effected by an even or uneven number of out-of-balance masses mounted on one of the tools.

The direction of rotation, the weights and dispositions of the out-of-balance masses is such that their force components at right-angles to the line of movement of the tool (which is towards and away from the other tool) cancel out and their resultant force is along the line of movement of the tool.

One apparatus for reducing metals or alloys, in accordance with the invention, is shown diagrammatically in the accompanying drawings of which FiGURE l is a side elevational View with parts removed and FIGURE 2 is a front elevational view.

FIGURE 3 of the accompanying drawings shows diagrammatically a plan view partly in cross-section of part of an apparatus in accordance with the invention for reducing strip of an appreciable width, and

FIGURE 4 is a schematic illustration of the servocontrol mechanism of the reciprocating tup.

The apparatus broadly comprises a heavy base 1, a superstructure and a heavy tup 11 on which the out-ofbalance masses 25 and 26 are rotatably mounted. A pair of forging tools or dies 4 and 12 between which the metal is deformed are provided, a lower tool 4 on the heavy base 1 and an upper tool 12 on the tup 11.

Referring to the drawings, the reducing apparatus comprises a heavy base portion 1 which stands, preferably, on a large block of concrete having a considerable mass. Part of the base portion is formed as a cylinder 2 within which is slidably mounted a piston 3. The upper end of the piston has rigidly fixed to it a die or forging tool 4. The end portion 5 of the cylinder 2 remote from the forging tool 4- is connected to a source of hydraulic fluid (not shown) and the piston and cylinder arrange ment form a hydraulic jack safety device.

Two side frames 6 and 7 are mounted on the base portion 1, one at one side of the apparatus and the other at the other side of the apparatus. The side frames 6 and 7 are connected together at their upper ends by a bridge-piece 8. The side frames 6 .and 7 support guide pillars 9 and 10.

A main oscillating mass or tup 11, to the lower end of which is rigidly secured a forging tool 12, has lugs 13, 14, 15 and 16 which closely surround the guide pillars 9 and 10 so that the tup 11 is guided for up and down movement only. The two forging tools 4 and 12 lie one above the other.

The upper end portion of the tup 11 is wider than the end which is secured to the forging tool 12. As shown in FIGURE 2 the wider end portion is bifurcated, each bifurcation 17, 18 provides a bearing for two shafts 19, 20, each shaft 19, 20 is rotatable in the bearing 17 or 18 by means of Cardan shafts (only one of which, 21, is visible in FIGURE 2) which are driven in opposite directions through a gear box 48 by an electric motor (not shown).

Each rotating out-of-balance mass arrangement comprises a compact mass of metal 25 or 26, such as a solid sphere or cylinder, connected by a web 23, to a hydraulic cylinder 27 containing a free piston 29 and is mounted on a shaft 19 or 20 on the tup 11. The drive is by a flexible shaft 21 connected to an electric motor mounted on the superstructure. The free piston 29 can be moved hydraulically along the cylinder 27 towards or away from the compact mass 25 or 26 so as to balance or unbalance the arrangement during rotation.

Each shaft 19 and 20 carries a "web '23 or 24 and one end of each web carries a mass 25 or 26 which is eccentric with respect to the shaft 19 or 20. Each web portion 23 and 24 includes a cylinder 27 or 28 and within each cylinder is a sliding mass 29 or 30 in the form of a free piston. The end portion of each cylinder 27 or 28 remote from mass 25 or 26 may be supplied with fluid under pressure from an external fluid source (not shown) by way of a pipe 31 communicating with an axial bore on the shaft 19 or 20. Fluid 'within the cylinder 27 and 28 may be removed by way of another bore in the shaft 19 and 20 which communicates with a pipeline 32 and returned to the external fluid source (not shown).

When the masses are unbalanced, rotation will produce oscillation of the tup 11 which is permitted to move only in a vertical plane by guides 9 and 10 on the superstructure. Thus the tool 12 attached to the tup 11 is caused to move towards or away from the tool 4 fixed to the base 1. Metal introduced between the tools is deformed to an extent depending upon the resistance to deformation of the metal and upon the weight of the tup 11. The frequency of oscillation of the tup 11 depends upon the speed of rotation of the unbalanced masses, whilst the amplitude depends upon the position of the compact mass in relation to the axis of rotation. Thus, the greater the speed of rotation, the higher the frequency, and the further the compact mass from the axis of rotation, the greater the amplitude.

The masses 25 and 26 and the sliding masses 29 and 30 are such that when the latter are at the end of the cylinders 27 and 28, remote from the former, the rotating assembly is in balance and when the shafts 19 and are rotated, no upward and downward movement of the tup 11 occurs. As the sliding masses 29 and 30 move along the cylinders 27 and 28 towards the shafts 19 and 20, and the shafts l9 and 20 are rotated in opposite direc tions, the tup 11, and hence the forging tool 12, move towards and away from forging tool 4. The amplitude of the movement of the forging tool 12 is dependent upon the distance of the sliding masses 29 and 30 from the shafts 19 and 20, the maximum amplitude being when the sliding masses are at the ends of the cylinders 27 and 28 near to the masses and 26. The frequency of the movement is dependent upon the speed of rotation of the shafts.

During operation the thickness of the metal is pr0gressively reduced to the desired thickness by blows from the tup 11. The limit of downward travel of the upper tool 12 is made to coincide with the desired metal thickness by means of an amplitude control device operated by movement of the tup 11. A convenient manner of doing this is to provide on the tup 11 an adjustable arm 41 which depresses, at the end of the tups downward stroke, the core of an induction coil 42. The core is restrained from rapid upward movement by a friction mechanism. The output of the coil 42 is a measure of the minimum tool separation distance and is fed to an amplifier 43. The output from the amplifier 43 is utilized to regulate, through a servo-mechanism S and valve V, the hydraulic fluid pressure which controls the position of the free piston 229 and in relation to the axis 10f rotation. Alteration of the position of the piston 29 and 30 alters the out-of-balance effect.

The arm 41 is arranged to depress the core of the pickup coil 42 at the bottom extremity of its travel, rapid upward movement of the core being restrained by a friction-driven mechanism (not shown). The output of the coil 42 is thus a measure of the minimum tool separation distance and is fed to an amplifier 43. The output from the amplifier 43 controls, through a suitable servocontrol mechanism S and a hydraulic valve V, the pressure of the fluid supplied to the cylinders 27 and 28 from a supply H, as shown in FIGURE 4.

The servo-valve S may be of any known construction, such as an electrically operated solenoid valve which actuates the movable valve member of ordinary hydraulic control valves H. The particular form of servo control and hydraulic valve is not essential to the operation of the apparatus, and may take the form of any suitable known hydraulic servo-valve.

Prior to the reduction of a sheet or strip of metal the position of the arm 41 is adjusted so that the output from the induction coil 42 is zero when the tools 4- and 12 are separated by a distance equal to the desired outgoing strip thickness. Variation of outgoing strip thickness and therefore of the maximum tool separation distance from the set distance during operation of the machine results in an output from the induction coil 42 which, through the servo-mechanism V, adjusts the position of the sliding masses 19 and 20 in a manner arranged to correct the error in strip thickness produced.

In this method of strip reduction of metals and al oys there is no restriction on the shape of the deforming faces of the forging tools analogous to that imposed in rolling mills by the radius of the rolls used. Consequently, in this apparatus, contact areas and shapes can be varied as is necessary to effect the reduction required. Furthermore, the deformation of the sheet is the result of the conversion of the kinetic energy of the oscillating tup and will be uniform across the width of strip without camber effects.

Strip or sheet 33 which is to be reduced in thickness is fed by two or more rolls 34 and 35 which are driven by an electric motor 36. During feeding towards and away from the forging tools 4 and 12 the strip or sheet is supported by supporting rolls 37. Before reaching the forging tools 4 and 12 the strip or sheet passes through an electrical induction heating device 38 having near each end thereof, guides 39 and 4% to prevent the strip or sheet touching the induction heating device. After reduction, the strip or sheet is wound on to a coiler (not shown).

For the production of strip, the tools are made to a profile such that the strip is progressively reduced by inclined tool faces as it passes through the tool.

The strip to be reduced in the apparatus is fed through the die by a very small increment between each stroke of the tup so that the strip is stationary when it is engaged by the tools. The rate of feeding may, for example, be between 1 and 6 inches per minute. The required production rate may necessitate oscillation of the tup at high frequency. For example, at a feed rate of 3 inches per minute, the frequency of oscillation of the tup is 1000 strokes per minute, the strip being fed by increments of 0.003 inch per stroke.

Whilst certain metals can be cold-reduced, it may be necessary to hot-forge harder metals and for this purpose an induction heating unit may be used to heat the metal just prior to entering the tools.

If desired, the tools may be cooled during the forging operation by passing Water through passages in the tool assembly.

In one embodiment described above, the forging tools lie one above the other and one of the forging tools moves in a vertical direction. In another embodiment of the invention the forging tools are side by side and one or both of them moves or move in a horizontal direction. In such an embodiment, springs may be necessary to effect efiicient to and fro movement of the forging tools.

Referring to FIGURE 3, the strip is passed between two forging tools, one of which is fixed and the other of which moves upwardly and downwardly with respect to the fixed one. The movable tool is secured to a tup 51. Two out-of-balance masses 52 and 53, the webs 54 and 55 of which carry piston and cylinder arrangements 56 and 57 (similar to those described with reference to FIG- URES l and 2), and four out-of-balance masses 58, 59, 60 and 61, are carried on shafts 62 and 63 which are rotatably mounted on the tup 5].. The tup 51 has lugs 64 and 65 which surround vertical pillars 66, 67, 68 and 69.

The structure of the modification shown in FIGURE 3 is identical to that of FIGURES l and 2 except that additional out-of'balance masses 58, 61 are provided, and no balancing masses such as free pistons are provided for these masses, although this modification also includes out-of-balance masses 52, 53 provided with similar pistons and adjusting means as the structure of FIGURES 1 and 2. The purpose of the modified construction is merely to distribute the driving forces across the width of the tup.

We claim:

1. An apparatus for reducing the thickness of meta] strip comprising: a pair of conforming tools; means for feeding the strip through a gap formed by the conforming tools; a reciprocable member joined to one of said tools; means for effecting reciprocation of said member to move said tools towards and away from the other, including a prime mover, a shaft continuously rotatable by said prime mover, a first mass eccentrically mounted fixedly upon said shaft, a second mass eccentrically mounted fixedly upon said shaft, a second mass eccentrically mounted upon said shaft diametrically opposite said first mass and variable in its eccentricity by movement along a radius to adjustably control the total unbalance of said masses, and means for transmitting components of the forces developed in said shaft along a diameter thereof to said reciprocable member.

2. An apparatus as claimed in claim 1 in which the position of the second mass is variable during operation of the apparatus.

3. An apparatus as claimed in claim 2 in which the position of the second mass is hydraulically controlled.

4. An apparatus as claimed in claim 1 including two rotatable shafts, each shaft having first and second masses mounted thereon.

5. An apparatus as claimed in claim 1 in which the first and second masses may be completely balanced so that no net force results in the shaft.

References (Zited in the file of this patent UNITED STATES PATENTS 455,598 Malin July 7, 1891 570,816 Price Nov. 3, 1896 1,484,490 Goldschmidt Feb. 19, 1924 1,620,201 Goldschmidt Mar. 8, 1927 1,855,446 Goldschmidt Apr. 26, 1932 2,026,666 Benham Jan. 7, 1936 2,039,680 Byers May 5, 1936 2,246,612 Ackerman June 24, 1941 2,350,921 Pinazza June 6, 1944 2,545,245 Stutz Mar. 13, 1951 2,617,319 Richards Nov. 11, 1952 2,933,626 Giboney Apr. 19, 1960 FOREIGN PATENTS 213,027 Great Britain Mar. 27, 1924 260,028 Great Britain Oct. 18, 1926 

